The Department of Social and Health Services (DSHS) seeks review óf a Court of Appeals determination that DSHS is estopped from recouping public assistance benefits it overpaid to the respondents. Mikhail Kramarevcky and Olivia Jinneman, the respondents, both qualified for public assistance benefits and provided DSHS with accurate information concerning their eligibility. At some point, DSHS began sending both respondents and their respective families an overpayment of benefits for which they were not qualified. They received these overpayments solely as a result of error on the part of DSHS, and through no fault or error of their own. The Court of Appeals held that equitable estoppel applied under the facts of these cases to estop DSHS from recouping these overpayments. We agree and affirm.
I
In 1987, a suit entitled Chaplin v. Sugarman, cause 87-2-01239-2 (Jan. 2,1990) was filed in Thurston County Superior Court. The plaintiffs were a class of persons who had received overpayments of Medicaid or family assistance benefits because of some DSHS error. They sought a declaratory ruling that administrative law judges (ALJs) have the authority to consider equitable estoppel ás a defense to the Department's recoupment claims.
DSHS opposed the action. It argued ALJs do not have the authority to consider equitable estoppel in the context of public assistance overpayments, and federal law requiring DSHS to recoup overpayments precluded application of estoppel. The Department also argued its acts of overpaying benefits should be deemed ultra vires under State v. Adams, 107 Wn.2d 611, 732 P.2d 149 (1987), thus precluding any applica-. tion of the doctrine of equitable estoppel.
The Superior Court issued a memorandum opinion ruling in favor of the plaintiffs and rejecting each of the Department's arguments. DSHS did not appeal this ruling. The Superior Court entered an order directing DSHS to inform all class members of their right to request a hearing and to assert the defense of equitable estoppel. Mikhail Kramar*741evcky and Olivia Jinneman were among the class of persons DSHS notified pursuant to the court's order.
Mikhail Kramarevcky is a refugee from the former Soviet Union. He arrived in the United States in April 1989 with his wife and minor son, Andre. The family speaks very little English and relied exclusively on DSHS for advice regarding their eligibility for public assistance. Between September 1989 and October 1990, the Kramarevckys received income and food assistance payments from DSHS under the Department's Family Independence Program (FIP).
In December 1989, Kramarevcky found a job and reported this to DSHS. He promptly gave the Department a copy of his first paycheck. DSHS failed, however, to follow its established procedures and did not send Kramarevcky monthly income report forms to complete and return. Uncertain as to what to do, Kramarevcky collected his wage receipts and brought them to DSHS in April 1990.
As a result of its failure to follow established procedures, DSHS did not take into account Kramarevckys earned income when it computed his family's financial and food cash benefits during the 4-month period from February through May 1990. The Department later determined that Kramarevcky and his family had received an overpayment during this 4-month period of $1,375 in financial assistance and $262 in food assistance. DSHS sought to recoup this money from Kramarevcky.
An administrative hearing was held regarding these over-payments. Kramarevcky testified at the hearing with the aid of an interpreter. The ALJ found Kramarevcky had followed all proper procedures, had no reason to believe his eligibility had ceased, and could have been eligible for refugee job training reimbursement had he not received the overpayments. The ALJ also found both Kramarevcky and his wife are now partially disabled and have no income or resources with which to repay DSHS. The ALJ concluded each element of the defense of equitable estoppel had been met, and DSHS was estopped from recouping the overpaid amounts.
*742Olivia Jinneman, the other respondent in this case, received categorically needy medical assistance under the Aid to Families with Dependent Children (AFDC) program between January 1988 and June 1989. This program is administered by DSHS. Jinneman provided accurate information to DSHS concerning her son Brandon's date of birth. Brandon turned 18 years old on April 29,1988. He was not attending school at the time of his 18th birthday, and the family unit became ineligible for the AFDC program as a result. DSHS continued, however, to send Jinneman medical coupons from May 1, 1988, through June 30, 1989. Upon discovering its error, DSHS terminated Jinneman's medical assistance and assessed a $1,759.94 overpayment against her for medical assistance received during that 13-month period.
An administrative hearing was held regarding these over-payments. Jinneman testified at this hearing. The AU found that "[h]ad [Jinneman] been appropriately advised of medical assistance eligibility, she would have obtained alternative care such as from women's clinics, utilized medicine alternatives, or used other medical providers such as the fire department". finding of fact 3 (Dec. 6, 1990). The AU also found Jinneman's average disposable income for the 11 months preceding the hearing was $527 a month, an amount barely adequate to meet her needs. As in Kramarevcky's case, the AU found each element of the defense of equitable estoppel had been met, and ruled DSHS was estopped from recouping the overpayments it had made to Jinneman.
DSHS sought review of the AUs' decisions from a review judge in both the respondents' cases. In both cases, the review judge adopted the AUs' findings of fact, but reversed the conclusions of law. The review judge ruled DSHS was not estopped from recouping the overpayments from either Kramarevcky or Jinneman.
The respondents sought judicial review. The Cotut of Appeals granted direct review and consolidated the two cases. The cotut reversed the review judge and reinstated the AUs' determinations that DSHS was estopped from *743recouping the overpayments it made to the respondents. Kramarevcky v. Department of Social & Health Servs., 64 Wn. App. 14, 822 P.2d 1227 (1992). DSHS sought review of the Court of Appeals decision, and this court granted review.
II
The issue in these two consolidated cases is whether DSHS is equitably estopped under the facts of these cases from recouping public assistance benefits it overpaid to the respondents. The elements of equitable estoppel are: (1) a party's admission, statement or act inconsistent with its later claim; (2) action by another party in reliance on the first party's act, statement or admission; and (3) injury that would result to the relying party from allowing the first party to contradict or repudiate the prior act, statement or admission.1 Robinson v. Seattle, 119 Wn.2d 34, 82, 830 P.2d 318, cert. denied, 121 L. Ed. 2d 598 (1992). Equitable estoppel is based on the principle that:
a party should be held to a representation made or position assumed where inequitable consequences would otherwise result to another party who has justifiably and in good faith relied thereon.
Wilson v. Westinghouse Elec. Corp., 85 Wn.2d 78, 81, 530 P.2d 298 (1975).
Equitable estoppel against the government is not favored. See Finch v. Matthews, 74 Wn.2d 161, 169, 443 P.2d 833 (1968). Consequently, when a party asserts the doctrine against the government, two additional requirements must be met: equitable estoppel must be necessary to prevent a manifest injustice, and the exercise of governmental functions must not be impaired as a result of the estoppel. Shafer v. State, 83 Wn.2d *744618, 622, 521 P.2d 736 (1974); Finch, 74 Wn.2d at 175. Courts should be most reluctant to find the government equitably estopped when public revenues are involved. Harbor Air Serv., Inc. v. Board of Tax Appeals, 88 Wn.2d 359, 367, 560 P.2d 1145 (1977).
A party asserting equitable estoppel against either the government or a private party must prove each element of estoppel with clear, cogent and convincing evidence. Pioneer Nat'l Title Ins. Co. v. State, 39 Wn. App. 758, 760-61, 695 P.2d 996 (1985) (equitable estoppel asserted against government); Colonial Imports, Inc. v. Carlton Northwest, Inc., 121 Wn.2d 726, 853 P.2d 913 (1993) (equitable estoppel asserted against private party). Under this burden of proof, the trier of fact must be convinced the fact in issue is "highly probable". Colonial Imports, 121 Wn.2d at 735; In re Sego, 82 Wn.2d 736, 739, 513 P.2d 831 (1973).
The Department has not placed the first two elements of equitable estoppel at issue. The Department apparently concedes its act of overpaying benefits to the respondents does satisfy the first element of estoppel, which involves an "act" inconsistent with a party's later claim. DSHS consequently has not raised the issue of whether its act of overpaying benefits is ah ultra vires act to which equitable estoppel may not apply. See State v. Adams, 107 Wn.2d 611, 732 P.2d 149 (1987). DSHS did raise this argument before the Superior Court in Chaplin, and the Superior Court rejected it. See Chaplin v. Sugarman, Thurston Cy. cause 87-2-01239-2 (Jan. 2, 1990), mem. op. at 9. DSHS did not appeal the Superior Court's ruling and did not raise or brief the ultra vires question before the Court of Appeals or this court. The respondents argue collateral estoppel precludes reconsideration of issues decided by the Superior Court in Chaplin, and DSHS has not presented any briefing disputing this contention. This issue therefore remains for determination in an appropriate future case.
DSHS does argue, however, that the third element of equitable estoppel, which involves "injury" to the relying party, has not been established. The Department maintains that public *745assistance recipients who received some overpayment for which they are later deemed substantively ineligible can never establish an "injury", as a matter of law, regardless of the particular facts of each case.
The Court of Appeals relied on the following two cases in determining that a party's substantive ineligibility is not a per se bar to establishing an "injury" for the purposes of equitable estoppel: Wilson v. Westinghouse Elec. Corp., 85 Wn.2d 78, 530 P.2d 298 (1975) and West v. Department of Social & Health Servs., 21 Wn. App. 577, 586 P.2d 516 (1978), review denied, 92 Wn.2d 1032 (1979).
In Wilson, the plaintiff had the option of either seeking early retirement with his private employer or seeking another position with the employer in a different capacity. He chose retirement based on the employer's representation regarding the amount he would receive as a monthly pension. A year later, the employer discovered it had overcalculated the plaintiff's pension benefits and sought to recoup the overpayments. The court held equitable estoppel precluded this recoupment. Wilson, 85 Wn.2d at 82. The court stated:
the plaintiff properly assumed that the payments tendered to him were accurate and structured his life accordingly. To allow [the employer] to repudiate its original representations and to require the plaintiff to repay the excess payments at this time would be highly inequitable and prejudicial.
Wilson, 85 Wn.2d at 82. Like the respondents in these cases, the plaintiff in Wilson was not substantively eligible for the overpayments. However, this fact did not bar consideration of whether equitable estoppel applied under the facts of that case.
DSHS maintains Wilson does not apply because estoppel was sought in that case against a private party, not the government. However, the "injury" element apphes under Washington law to claims of estoppel against both private and governmental entities. Colonial Imports, at 734 (private party); Board of Regents v. Seattle, 108 Wn.2d 545, 551, 741 P.2d 11 (1987) (government). The court's interpretation of the "injury" element in Wilson therefore has relevance for *746determining whether "injury" can be established in these cases.
The Court of Appeals also relied on West v. Department of Social & Health Servs., 21 Wn. App. 577, 586 P.2d 516 (1978) , review denied, 92 Wn.2d 1032 (1979) in interpreting the "injury" requirement. In West, a mother placed her children in foster care. At the time, she was not properly informed by DSHS that she would incur financial obligations as an immediate result of this placement. The Department later sought payment of this financial obligation. The Court of Appeals held the elements of equitable estoppel had been met, and DSHS was estopped from collecting payment from the mother. West, 21 Wn. App. at 580. The mother in West was not substantively eligible for cost-free foster care. However, this substantive ineligibility did not bar the court from considering whether equitable estoppel applied under the facts of the case.
DSHS argues West should not be considered because it is not consistent with this court's decision in Griffin v. Department of Social & Health Servs., 91 Wn.2d 616, 590 P.2d 816 (1979) . This contention lacks merit. In Griffin, parents placed their child in foster care and were informed at the time of their obligation to pay for this care and did not dispute their ability to pay. Griffin, 91 Wn.2d at 625-26. The court rejected the parents' later contention that equitable estoppel precluded DSHS from billing the parents for the child's care. Griffin, 91 Wn.2d at 631.. Unlike the parents in Griffin, the mother in West was not informed of her support obligation at the time she placed her child in foster care. West is therefore distinguishable and not inconsistent with Griffin.
Both West and Wilson support the Court of Appeals determination that a party's substantive ineligibility to receive a benefit is not a per se bar to establishing an "injury" for equitable estoppel purposes, and we agree with this determination. We note that courts in other jurisdictions have also reached decisions consistent with this conclusion. See, e.g., Fraga v. Department of Health & Rehab. Servs., *747464 So. 2d 144 (Fla. Dist. Ct. App. 1984); Kruse v. Department of Public Aid, _ Ill. App. 3d _, 596 N.E.2d 743 (1992). The parties in these cases are therefore not barred from establishing an "injury" for the purposes of equitable estoppel.
DSHS also argues the Court of Appeals erred, because it held a party can always establish the "injury" requirement merely through his or her obligation to repay the overpayments. This argument mischaracterizes the nature of the Court of Appeals holding. The Court of Appeals determined more was required to estabbsh "injury" than the mere obhgation to repay. The court's opinion indicates that parties meet the "injury" requirement if they reasonably rely on the actions of another and change their position to their detriment as a result of this rebanee. Kramarevcky, 64 Wn. App. at 22.
This interpretation of the "injury" requirement is consistent with prior Washington cases. To estabbsh an "injury" for equitable estoppel purposes, a party must estabbsh he or she justifiably rebed to his or her detriment on the words or conduct of another. See Safeco Ins. Co. of Am. v. Butler, 118 Wn.2d 383, 405, 823 P.2d 499 (1992). In Washington, injury, prejudice and detrimental rebanee have been used interchangeably to express the requirement that a party asserting equitable estoppel must show a detrimental change of position. State ex rel. Shannon v. Sponburgh, 66 Wn.2d 135, 143-44, 401 P.2d 635 (1965); Woodworth v. School Dist. 2, 92 Wash. 456, 463, 159 P. 757 (1916); Butler v. Supreme Court of Indep. Order of Foresters, 53 Wash. 118, 124, 101 P. 481 (1909).
The Court of Appeals determined "injuiy" in the form of detrimental rebanee has been estabbshed under the facts of these cases, and it rebed on the AUs' findings of fact in reaching this conclusion. In Kramarevcky's case, the ALJ found that had DSHS correctly accounted for his earned income, Kramarevcky could have been ehgible for job training reimbursement through the Refugee Assistance Pro*748gram. See WAC 388-55 (refugee assistance). In Jinneman's case, the ALJ found that if Jinneman had been properly advised of her eligibility, she would have obtained alternative care, utilized medicine alternatives, or used other medical providers such as the fire department or women's clinics.
The review judge adopted the AUs' findings in both Kramarevcky's and Jinneman's case, noting the findings were based on the AUs' opportunity to assess the credibility of the witnesses. The Court of Appeals determined these findings were sufficient to establish detrimental reliance in these two cases, and DSHS has not sought review of this determination from this court. The "injury" requirement has therefore been met in these cases.
DSHS next argues the Court of Appeals erred in determining the "manifest injustice" element had been met in these cases. The Department maintains the Court of Appeals erred because it inquired into the hardship the individual respondents would suffer if DSHS were allowed to recoup the overpayments. DSHS argues the court should have instead evaluated manifest injustice from the standpoint of all public assistance recipients who would suffer if DSHS were estopped because less money would be available for them.
The Department fails to cite any authority which lends support to the position that manifest injustice is to be determined by reference to third parties not involved in the particular proceeding. It is logical and appropriate for courts to inquire whether equitable estoppel is required to prevent manifest injustice to the party seeking estoppel. See, e.g., Harbor Air Serv., Inc. v. Board of Tax Appeals, 88 Wn.2d 359, 367, 560 P.2d 1145 (1977); Hasan v. Eastern Wash. Univ., 24 Wn. App. 829, 834-35, 604 P.2d 191 (1979).
In analyzing whether the respondents met their burden of showing they would suffer a manifest injustice, the Court of Appeals considered the following factors: (1) the respondents did not have the resources to repay the debt without drawing on funds currently needed to meet their most basic needs; (2) the respondents provided DSHS with timely and accurate *749information, and the overpayments resulted solely from the Department's error; (3) the overpayments involved a continuation of benefits for which the respondents had been eligible, and there was no reason they would have been alerted to the fact of overpayment; and (4) there was no evidence the respondents were abusing the public assistance system. Kramarevcky, 64 Wn. App. at 23-24. These factors establish the "manifest injustice" element has been met in these cases.
DSHS also argues the Court of Appeals erred in determining that application of estoppel in these two cases will not impair governmental functions. The Court of Appeals observed the overpayments in this case resulted from DSHS' error alone, and estoppel may provide an impetus for DSHS to more adequately monitor and control such payments. Kramarevcky, 64 Wn. App. at 26. DSHS strenuously objects to the Court of Appeals observation that estopping DSHS in these cases could improve rather than impair governmental functions. However, the Department has not cited adequate authority supporting the contention that the Court of Appeals otherwise erred in concluding estoppel would not impair governmental functions in these cases.
Finally, DSHS argues the respondents should be denied the defense of equitable estoppel as a matter of public policy. The Department points out it is required by statute to take necessary steps to recoup overpaid amounts from public assistance recipients. See 42 U.S.C. § 602(a)(22). DSHS maintains the application of equitable estoppel would be inconsistent with this statutory requirement, and therefore estoppel should not apply in this context. However, estoppel principles have been recognized in Washington for at least the past 100 years. See, e.g., Spokane St. Ry. v. Spokane Falls, 6 Wash. 521, 33 P. 1072 (1893) (city estopped from claiming it did not authorize building of railroad tracks). The court is therefore reluctant to find an abrogation of estoppel principles absent a clear showing of legislative intent. See Ames v. Department of Labor & Indus., 176 Wash. 509, 513-14, 30 P.2d 239, 91 *750A.L.R. 1392 (1934). DSHS has not provided adequate support for the contention that such an intent has been evidenced in this context.
Ill
DSHS raises additional arguments that it did not raise below, and we decline to consider these arguments. RAP 2.5(a); Kennedy v. Seattle, 94 Wn.2d 376, 383, 617 P.2d 713 (1980). We conclude equitable estoppel properly applies under the facts of these cases. The Court of Appeals is affirmed.
Andersen, C.J., and Utter, Smith, and Guy, JJ., concur.
In addition to satisfying each of these elements, the party asserting the doctrine must be free from fault in the transaction at issue. Mutual of Enumclaw Ins. Co. v. Cox, 110 Wn.2d 643, 651, 757 P.2d 499 (1988). A party may not base a claim of estoppel on conduct, omissions, or representations induced by his or her own conduct, concealment, or representations. Mutual of Enumclaw, 110 Wn.2d at 651 (citing 31 C.J.S. Estoppel § 75, at 453-54 (1964)). This principle is known as the "clean hands" doctrine. Mutual of Enumclaw, 110 Wn.2d at 650. The respondents in this case have met this requirement.